- The thin client reborn: Thin clients are an age-old dream of centralized IT – fat centralized servers control thin “dumb” terminals (they probably never completely got over the fact that personal computers have largely replaced mainframes). Chromebooks might make that dream come true without sacrificing usability, because they are not dumb terminals. For example, you can get centralized control , but Chromebooks also work when they are not connected, thanks to support for offline operation.
- Who will buy chromebooks? They are too expensive for consumers who will see them as doing less than other mobile devices while not being significantly cheaper. Prices starting at $349 are not low enough for impulse purchases, which could have generated volume and created a niche below tablets, for casual users. On the other hand, owners of mass installations will love the ease of administration, security features and the subscription pricing that includes tech support.
- Increasing the importance of web technology: Webapps are already attractive for businesses, because of ease of deployment and platform independence (including all mobile operating systems!). The Chrome OS business features  further increase the attraction.
- Restricted environment: Chrome OS has many similarities to the iPad when it comes to protecting less technically savvy users from themselves: little room to cause damage via the file system, easy installation of apps, automatic app updates, automatic saving of data.
- Very “googly”: Echoing Gruber’s sentiments, I think that Chrome OS fits very naturally into Google’s web-centric universe. It lets the whole company work together (cloud services, webapps, etc.).
- The role of Chrome OS in history: It is not yet sure that Google will have the patience to stick with Chrome OS in the long term, especially because it has an internal competitor in Android. But even then Chrome OS is important because it drives the state of the art of web applications. Should it not survive on its own, it will probably end up as a compatibility layer for stand-alone webapps on Android, desktops, etc.
- Missing from Chrome OS: Syncing is still limited and difficult to implement. For example, peer-to-peer operation would be nice in scenarios where one is offline but has several devices running the same webapp. 
A few thoughts on Chromebooks and Chrome OS
Update 2011-12-01: Is Google's Chromebook a failure?